Abstract
Background: Periodontal disease, a common disorder of the tissue surrounding and supporting the teeth, is a major cause of tooth loss in adults. Periodontal infection by oral microorganisms may have systemic effects and has been associated with several types of cancer. However, its association with liver cancer has only been examined in two prospective studies, both of which had very small number of liver cancer cases (n < 20).
Methods: We examined the association of tooth loss, as a proxy measure of periodontal infection, with primary liver cancer incidence and chronic liver disease mortality in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) study, a prospective cohort of male Finnish smokers (n = 29,096). Number of permanent teeth lost was assessed at study baseline (1985-1988). We used Cox proportional hazards models to calculate multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs). As a sensitivity analysis, we conducted a nested case-control study to assess confounding by hepatitis B or C virus (HBV or HCV) infection and seropositivity of Helicobacter pylori.
Results: A total of 213 incident primary liver cancers occurred during a mean follow-up of 17 years. Having 11-31 permanent teeth lost was associated with a 42% higher risk of liver cancer (HR=1.42, 95% CI: 1.01-1.98), and having all 32 teeth lost was associated with a 45% higher risk of liver cancer (HR=1.45, 95% CI: 1.00-2.10), compared to having 0-10 teeth lost. In the sensitivity analysis, adjusting for Helicobacter pylori seropositivity yielded a modest attenuation of the effect estimate, whereas adjustment for HBV or HCV did not materially change the results. No consistent pattern was observed for liver disease mortality (n = 250 deaths).
Conclusions: In this study, greater number of teeth lost was associated with higher risk of primary liver cancer. Further investigations are warranted to clarify the role of periodontal infection in hepatocarcinogenesis and to determine the utility of tooth loss as a predictor of liver cancer development.
Citation Format: Baiyu Yang, Jessica L. Petrick, Christian C. Abnet, Barry I. Graubard, Stephanie J. Weinstein, Satu Männistö, Demetrius Albanes, Katherine A. McGlynn. Tooth loss, liver cancer incidence, and chronic liver disease mortality in the ATBC study. [abstract]. In: Proceedings of the AACR Special Conference: Improving Cancer Risk Prediction for Prevention and Early Detection; Nov 16-19, 2016; Orlando, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2017;26(5 Suppl):Abstract nr A13.